Many geometric puzzles, adapted to educate children and amuse adults, have been proposed. I have discovered that it is possible to dissect a regular octagon to form at least one irregular octagon and one or more smaller pieces. The dissection is such that each of the smaller pieces takes the form of a rhombus, a square, a regular hexagon, or an irregular hexagon. The parts from eight dissected regular octagons may be assembled to form a large tessellated regular octagon. The puzzle provides an intimate knowledge of geometry and is an amusing and instructive one. By providing the pieces with various colors, beautiful octagonal designs may be made to appear when the puzzle is assembled.